right click new custom file type

[Hatsune Miku]

is there a way of making my windows 7 allowing me to chose the file extension for right click new

 

[Hacb]

there might be a way, but it most likely involves poking around in the registry, which you should only try if you know what you are doing because one wrong move could make your computer inoperable

 

[countzero]

i think this falls under the category shell extension.
ShellExView might help. but Hacb is right.
if it ain't really broke go have a nap.